METHOD OF GROWING PURE Ge THIN FILM WITH LOW THREADING DISLOCATION DENSITY

Abstract

Provided is a method of growing a pure germanium (Ge) thin film with low threading dislocation density using reduced pressure chemical vapor deposition (RPCVD), which includes growing a Ge thin film on a silicon (Si) substrate at a low temperature, performing real-time annealing for a short period of time, and growing the annealed Ge thin film at a high temperature. The grown Ge single crystal thin film can overcome conventional problems of generation of a Si—Ge layer due to Si diffusion, and propagation of misfit dislocation to a high-temperature Ge thin film.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims priority to and the benefit of Korean Patent Application No. 10-2008-0123326, filed Dec. 5, 2008, the disclosure of which is incorporated herein by reference in its entirety.BACKGROUND[0002]1. Field of the Invention[0003]The present invention relates to a pure germanium (Ge) single crystal layer, which is grown on a silicon substrate, and more particularly, to a method of forming a stress relaxed Ge single crystal thin film, low threading dislocation density and good surface roughness using reduced pressure chemical vapor deposition (RPCVD).[0004]2. Discussion of Related Art[0005]Development of novel devices using heterojunctions of silicon (Si) and silicon-germanium (Si—Ge) or germanium (Ge) has been conducted for several decades. These devices generally utilize a difference in band-gap energy between Si and Ge, or high-mobility characteristics generated due to stress applied according to a difference of lattice co...

AI Technical Summary

Benefits of technology

[0014]One aspect of the present invention provides a method of growing a germanium (Ge) single crystal thin film with low threading dislocation density using reduced pressure chemical vapor deposition (RPCVD), including: growing a Ge thin film on a silicon (Si) substrate at a low temperature; performing real-time annealing for a short period of time; and growing the annealed Ge thin film at a high temperature.

[0015]Another aspect of the present invention provides a method of growing a Ge single crystal thin film with low threading dislocation density using RPCVD, including: growing a Ge thin film on a Si substrate at a low temperature; performing real-time annealing for a short period of time; growing a Si—Ge thin layer after real-time annealing; and growing the annealed Ge thin film at a high temperature on the Si—Ge thin layer.

Problems solved by technology

The threading dislocation propagated to the surface may cause defects of a thin film to be formed thereon, deteriorating device's characteristics or causing leakage current.

However, since this method requires high-priced UHVCVD equipment, and annealing cannot be performed in UHVCVD, rapid thermal processing (RTP) should be added, which is a time-consuming process taking almost 4 hours.

Further, due to interdiffusion between Si and Ge caused by high-temperature annealing, a Si—Ge layer is formed at an interface, affecting a change in band-gap and the device's characteristics.

The misfit dislocation may be a cause of deterioration of the device's characteristics during the fabrication of the device.

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